我有两种自定义分类法：

型号产品Type 可以是以下内容：

博客案例研究网络研讨会Subject 可以是：

我在WordPress后端有两个下拉菜单，用户可以从中选择type 和subject 他们想从resources （我的自定义帖子类型）。

例如，以下帖子存在于resources:

• Post 1: 标记为type 博客和subject 室外
• Post 2: 标记为type 博客和subject 室内
• Post 3: 标记为subject 室内

用户可以通过type 或subject. 我的意思是，不是两个都需要，只能选择一个。但是，如果用户选择了type 和subject, 我希望它显示带有两个标签的帖子。

Current approach:

$args = array(  
  \'post_type\' => \'resources\',
  \'post_status\' => \'publish\',
  \'posts_per_page\' => 8,
  \'tax_query\' => array(
    \'relation\' => \'AND\',
    array(
        \'taxonomy\' => \'type\',
        \'field\'    => \'slug\',
        \'terms\'    => $resource_type,
    ),
    array(
        \'taxonomy\' => \'subject\',
        \'field\'    => \'slug\',
        \'terms\'    => $resource_subject,
    ),
  ),
  \'tax_query\' => array(
    \'relation\' => \'OR\',
    array(
        \'taxonomy\' => \'type\',
        \'field\'    => \'slug\',
        \'terms\'    => $resource_type,
    ),
    array(
        \'taxonomy\' => \'subject\',
        \'field\'    => \'slug\',
        \'terms\'    => $resource_subject,
    ),
  )

);

• $resource_type: 是保存下拉列表值的变量type.
• $resource_subject: 是保存的下拉值的变量subject.

Current results:

过滤时subject 独自一人——这很有效。

当按筛选时type 独自一人——这很有效。

当同时使用两者进行过滤时，它不起作用。一、 e.我已过滤type 博客和subject 室内，它向我展示subject 户外立柱。

或者，在查询两者时，以下选项可以工作，但在仅选择一个选项时不起作用：

 $args = array(  
    \'post_type\' => \'resources\',
    \'post_status\' => \'publish\',
    \'posts_per_page\' => $card_count,
    \'tax_query\' => array(
      \'relation\' => \'AND\',
      array(
          \'taxonomy\' => \'type\',
          \'field\'    => \'slug\',
          \'terms\'    => $resource_type,
      ),
      array(
          \'taxonomy\' => \'subject\',
          \'field\'    => \'slug\',
          \'terms\'    => $resource_subject,
      ),
    )

  );

$args = array(
    \'post_type\'      => \'resources\',
    \'post_status\'    => \'publish\',
    \'posts_per_page\' => 8,
);

// Filtering by both \'type\' and \'subject\'.
if ( $resource_type && $resource_subject ) {
    $args[\'tax_query\'] = array(
        \'relation\' => \'AND\',
        array(
            \'taxonomy\' => \'type\',
            \'field\'    => \'slug\',
            \'terms\'    => $resource_type,
        ),
        array(
            \'taxonomy\' => \'subject\',
            \'field\'    => \'slug\',
            \'terms\'    => $resource_subject,
        ),
    );
}
// Filtering by \'type\' only.
elseif ( $resource_type && ! $resource_subject ) {
    $args[\'tax_query\'] = array(
        array(
            \'taxonomy\' => \'type\',
            \'field\'    => \'slug\',
            \'terms\'    => $resource_type,
        ),
    );
}
// Filtering by \'subject\' only.
elseif ( $resource_subject ) {
    $args[\'tax_query\'] = array(
        array(
            \'taxonomy\' => \'subject\',
            \'field\'    => \'slug\',
            \'terms\'    => $resource_subject,
        ),
    );
}